[Telemetry] Don't create a new Tab object at each navigation.

tools/telemetry/telemetry/core/extension_unittest.py

Index: tools/telemetry/telemetry/core/extension_unittest.py
diff --git a/tools/telemetry/telemetry/core/extension_unittest.py b/tools/telemetry/telemetry/core/extension_unittest.py
index 31f1e1b36fb4932b0bac2b81ebd07c223deae9be..bc5fd78ded9ab7e69a92fe78338af99f014f7bf7 100644
--- a/tools/telemetry/telemetry/core/extension_unittest.py
+++ b/tools/telemetry/telemetry/core/extension_unittest.py
@@ -50,15 +50,6 @@ class ExtensionTest(unittest.TestCase):
     self.assertEquals('abcdef',
                       self._extension.EvaluateJavaScript('_testVar'))
 
-  def testDisconnect(self):
-    """Test that ExtensionPage.Disconnect exists by calling it.
-    EvaluateJavaScript should reconnect."""
-    if not self._extension:
-      logging.warning('Did not find a browser that supports extensions, '
-                      'skipping test.')
-      return
-    self._extension.Disconnect()
-    self.assertEquals(2, self._extension.EvaluateJavaScript('1+1'))
 
 class NonExistentExtensionTest(unittest.TestCase):
   def testNonExistentExtensionPath(self):